Apparatus for applying and settling coatings



y 1953 J. B. LlNbsAY 2,646,769

APPARATUS FOR APPLYING AND SETTLING COATINGS Filed Feb. 24, 1949 9 Sheets-Sheet l INVENTOR JAMES B LINDSAY m .4

ATTO .;Y

y 1953 J. B. LINDSAY 2,646,769

APPARATUS FOR APPLYING AND SETTLING COATINGS :Filed'Feb. 24, 1949 9 Sheets-Sheet 2 r IIP-- 50 57 .53 1 NTOR 5/ a; JAMES LINDSAY WM d.

ATTO Y y 8, 1953 J. B. LINDSAY 2,646,769

APPARATUS FOR APPLYING AND SETTLI NG COATINGS Filed Feb. 24, 1949 9 Sheets-Sheet 3 INVENTOR JAMES B. LlNDSAY ATTOR Y July 28, 1953 v J. B. LINDSAY 2.6462769 APPARATUS FOR APPLYING AND SETTLING COATINGS Filed Feb. 24, 1949 9 Sheets-Sheet 4 I L90 g 5,, a/5

m 54 V/ a U I28 /5/ Y w u I /0 57 ,/66

INVENTOR JAMES B. LINDSAY ATTOR Y July 28, 1953 I J. B. LIYNDSAY 2,645,769

APPARATUS. FOR" APPLYING AND SETTLING commas Filed Feb. 24, 1949 -9;s n ets-shet s I ny I III! III!Ill/IIII/II/IIIIIIII/III/IIIII/II/II/ III! 1 [E E2! @ggmgm July 28, j LINDSAY r APPARATUS FOR APPLYING AND sETTLING COATINGS Filed Feb. 24 1949 7 9 sheets-sheet 6 4 I40 I44 36 I50 INVENTOR JAMES B. LINDSAY July 28, 1953 J; B. LINDSAY APPARATUS FOR APPLYING AND SETTLI-NG COATINGS Filed Feb. 24, 1949" 9 sheets-sheet 7 INVENTOR JAMES LINDSAY B. LINDSAY APPARATUS FOR APPLYING AND SETTLING= COATINGS ,July 28, 1953 9 Sheets-Sheet 8 Filed Feb. 24, 1949 KENT QSNR I R A m m N N E L V m B m M A a V u VW wu- QR w 1 QS QR Q3 55% July 28, 1953 J. B. LINDSAY APPARATUS FOR APPLYING AND SETTLING COATINGS Filed Feb. 24, 1949 9 Sheets-Sheet 9 Q9 KS3 vwhkwim mxmq INVENTOR JAMES B. LINDSAY ATTO Y QR MR wk NR MR Em NR Patented July 28, 1953 UNITED STATES APPARATUS FOR APPLYING AND SETTLING COATINGS James B. Lindsay, Millburn, N. J., assignor to Radio Corporation of America, a corporation of Delaware Application February 24, 1949, Serial No. 78,077

11 Claims.

This invention relates to the formation of coatings and more particularly to an apparatus for facilitating the production of such coatings which are applied in the form. of a mechanical mixture or suspension and then allowed to settle out upon the surface to be coated.

One example of such coatings is the luminescent screen on the face or end of a cathode ray tube envelope which, insofar as I am familiar therewith, were applied by a so-called tilt table apparatus prior to the advent of the method and apparatus disclosed in the co-pending application of J. Kent Burton, Serial Number 67,964, filed December 29, 1948, in accordance with which objects having surfaces onto which particles suspended in solution are to be applied, are moved continuously and at a constant speed through various positions such as dispensing, settling, decanting, washing and drying.

Such screens usually consist of several ingredients which must be maintained separate until they are intermingled at the time the coating is to be formed and may include a concentrate of a phosphor, an electrolyte, a binder and water. When these ingredients are brought together in the proper proportions a luminescent screen consisting of a binder and a phosphor is formed from which excess liquid is removed and the screen dried. Not only should the ingredients be added in accurately measured quantities but the order in which they are added has also been found to afiect the quality of the screen formed. Furthermore the nature of these ingredients is such that if they come into contact with parts of the object other than that intended to receive the coating, such parts receive an objectionable film.

Heretofore such objects have been individually charged with coating ingredients necessitating the presence of an operator to perform this function and who had to exercise constant care to avoid smearing inner or outer surfaces of the tube envelope with coating ingredients. Then the screen forming particles were settled, care being taken to avoid mechanical shocks or vibration which would disturb the even settling of the particles and hence the uniform density of the screen.

Thus, a principal object of my invention is to provide an apparatus to facilitate the application of screens or coatings formed by the settling out of particles from mechanical solution onto the surface to be coated thereby.

Another object of my invention is the provision of such apparatus which is fully automatic in operation.

A further object is to provide such apparatus which operates substantially free from vibration and which produces substantially uniform coatings free from blemishes.

Yet another object is the provision of means 2 which facilitate the insertion and removal of objects to be coated by the apparatus.

A still further object is the provision of such apparatus which is so precise in its timed operations and which is so constructed as to reduce to a minimum or remove entirely the possibility that relatively fragile objects will become chipped, cracked or broken.

Other objects will appear as the nature of my invention is more fully understood from the following description taken in conjunction with the accompanying drawings wherein like parts are identified by identical numerals in the several views.

In the accompanying drawings, wherein is shown, by way of illustration, one of the embodiments which the present invention may take:

Figure 1 is a side elevational view on a reduced scale of an apparatus constructed in accordance with my invention;

Figure 2 is a fragmentary perspective view of the left end of the apparatus shown in Figure 1;

Figure 3 is a sectional view on an enlarged scale of the envelope holder with the carriage therefor shown in elevation;

Figure 4 is a plan View of a modified holder;

Figure 5 is a schematic View illustrating another embodiment of the means for guiding the carriages around the ends of the conveyor;

Figure 6 is a front elevational view of the dispenser;

Figure 7 is a plan view of the dispenser;

Figure 8 is a sectional view on an enlarged scale through the line 8--8 of Figure 6;

Figure 9 is a view similar to Figure 8 with the parts shown in position prior to actuation;

Figure 10 is a sectional view through the line i0|0 of Figure 9 with the discharge tubes shown open;

Figure 11 is a sectional view through the line lll| of Figure 9;

Figure 12 is a sectional View on an enlarged scale through the line l2--|2 of Figure 9;

Figure 13 is a side elevational view partially in section of the rinse and dry apparatus shown in Figure 1;

Figure 14 is a sectional view through the line [4-44 of Figure 1;

Figure 15 is a View along the line l5i5 of Figure 13 in the direction indicated;

Figure 16 is a schematic view of the hydraulic system for controlling the dispenser elevating mechanism;

Figure 17 is a schematic wiringdiagram of the apparatus; and

Figure 18 is a sectional view on an enlarged scale through the line [8-18 of Figure 13.

Referring first to Figure 1, it will be seen that my apparatus may include an endless belt type conveyor 20, a, dispenser 2i, rinse apparatus 22.

and drying apparatus 23. Objects such as cathode ray tube envelopes when loaded on a constantly moving conveyor at station A, are carried through dispensing station E where they automatically receive a charge of coating or screen forming ingredients from dispenser 2!. The envelopes continue in movement substantially undisturbed for a time long enough to .permit even settling of the coating. On arriving in position C the coating forming particles have settled and between C and D excess liquid is poured off. The pouring off of excess liquid is carried out in an extremely slow and steady manner to avoid disturbance of the screen or coating by the liquid. Then between E and G the coatings are set. Thus, at E the envelope necks may be rinsed while between F and G the screens or coatings may be air dried. On returning to A, the envelopes with screens formed thereon are removed.

The conveyor Referring now to Figures 1-6 in detail, conveyor 2B is seen to have a main supporting frame one adjacent each end thereof. A pair of drive sprockets 32, one in alinement with each of idler sprockets 3| are mounted to rotate with drive shaft 28 on opposite ends. On a separate support 33 which is not connected in any manner to frame 24 is a motor 34 connected to a source of electrical power supply and to a reduction gear 35 which in turn is connected through a system of resilient belts 3t and pulleys to one end of shaft 31. On the other end of shaft El is a worm gear 38 which meshes with a suitable gear 39 keyed to shaft 28. It is to be noted that the only connection between the main conveyor and the motor platform is the belts 36 which serve to prevent the transmission of undesirable vibration from the motor to the conveyor.

Also supported at each end of frame 2% are four substantially semi-circular guide plates All, one such plate being disposed outwardly of and concentric with each of the two idler sprockets 3i and the two drive sprockets 32. As most clearly shown in Figure 2, plates lil may be suitably connected to each bushing M in which the shaft 28 is rotatably mounted and to bushings 29 at the other end of conveyor 28. A channeled arcuate guide i2 is connected adjacent to the periphery of each guide plate ll! and has an outside track 43 and an inside track M forming arcuate channel 45. Each outside track 43 may be provided with a facing or layer 53a of resilient material such as rubber or the like.

Two roller link endless chains M5, one stretched over and in mesh with each set of alined drive and idler sprockets, form an upper course 20a and a lower course 2%. Rails are disposed one on each side of upper course 20a and lower course 201) and extend parallel to the same. Thus, there are four rails 41, the upper pair of which are clearly shown in Figure 6 while each rail of the lower pair is below one of the upper rails and in alinement therewith. Rails 4'! may be conriages.

4 nected to horizontal frame members 26 along their length and supported thereby in spaced relation with respect to the chains.

A plurality of carriages indicated generally at 48, Figures 2 and 3, are carried by the conveyor,

interconnecting the two chains and supported by the rails 47, while those carriages passing around the ends of the conveyor from the upper to the lower course or from the lower to the upper course are supported by the respective guides 32. Each carriage includes a cross piece 59 which is connected at each of its ends to the upper portions of side plates or trucks 5%. Each truck is recessed at one end thereof to receive a leading roll 5| and at the other end to receive a trailing roll '52. Trailing rolls '52 are rotatably mounted on pins 53 while leading rolls 5i are rotatably mounted on a stub shaft a at each end of a connecting rod 54 which extends between the side plates or trucks 5!) and thus serves to interconnect the centers of leading rolls M of the carriage. At the point where connecting rod 5s passes each chain it is connected thereto by flanges 55 and bolts 55 or the like. It is to be understood that while connecting rod 5 3 is rigidly connected to the chains, side plates or trucks 50 are free to rotate about stub shafts 56a and are therefore rotatable with respect to the chains the purpose of which will be more fully pointed out hereinbelow. Rotatably mounted on the outer surface of each side plate or truck 50 is a guide roll 5'! of such diameter and length as to extend beyond rails 41 and enter channel 45 and pass therethrough in rolling engagement with the corresponding outer tracks :3 as the carriages pass around the sprockets from the upper course to the lower course and also at the opposite end when they pass around the idler sprockets from the lower course to the upper course.

Each carriage 48 carries holders 53 connected in spaced relation on the outer or upper surface of cross pieces 49 (looking in the direction of Fig. 3) by means of bolts 59 or the like. As is apparent in Figure 6 each carriage may carry three such holders 58 though the apparatus may be designed for more or less as desired. Thus, in the present instance there are three lines of holders which extend longitudinally of the conveyor while the rows which extend transversely of the conveyor each consist of three holders and there are as many such rows as there are car- Each holder 58 includes a receiver having a base Bil and an upstanding annular wall 6|. Wall 6| hasv an annular recess or channel formed therein adjacent its upper or open end in which is positioned an endless inflatable tube 62 substantially D-shaped in cross-section. I have found that such a D-shaped tube permits the ready insertion and withdrawal of an object such as cathode ray tube envelope 53 when dedated and yet securely retains the envelopes in the holders when inflated. An air valve is connected to tube 62 by means of stem 54 which passes through an opening in wall 6 I.

Also connected to each cross piece 353 and de pending therefrom (Fig. 3) is an actuator bar which as will be seen operates various switches as it is carried around the path described by the carriages.

As is apparent in Figure l, dispenser Z5 is located over and adjacent one of conveyor 22. In alinernent with the conveyor and spaced from the other end thereof is a splash shield 66 (Fig. 2 having a trough 86a disposed to receive liquid collected by the shield and conduct the same to a container or sewer (not shown).

Carriages 48 are of such dimensions that rolls 5|, 52 on each side thereof are in registration with and travel on the corresponding rails of either the upper or lower course of the conveyor. As each carriage approaches the left hand end of upper rails 4! each guide roll 5i engages one of the arcuate outer tracks 43 on guide 42. The curvature of track 43 is such that as guide roll 51 travels along the same rolls El, 52 are maintained in contact with inside track 4 3 since the carriages are free to rock about the connecting rods 54. When the carriages complete the circuit of guides 42, 180 around the drive sprockets, their rolls have just been positioned on the lower rails and thus as the rolls leave the inside track 44 they are already rolling freely on said lower rails. When the carriages arrive at the right hand end of the lower course the guide rolls 5'! are once again similarly engaged by the arcuate guides 40 associated with idler sprockets 3| and the carriages are guided and supported around the idler sprockets as previously pointed out in connection with the drive sprocket end of the conveyor.

During operation the conveyor is constantly driven at a uniform speed by motor 34. The distance between the centers of shafts 2i and 28 is selected so that the carriages may traverse the path described by the conveyor at a relatively slow rate, approximately four to six inches per minute being satisfactory when luminescent screens are being settled. Another factor which must be considered is that after the envelopes are carried past the dispenser 2i sufiicient time must remain for the coating to settle out of solution onto the face of the envelopes before they are carried around the drive sprockets to the lower course. Thus, the maximum permissible speed will be determined by the length of the conveyor and the time required for settling. Since such coatings are sensitive to vibration it is necessary to maintain the rate at which the conveyor travels relatively slow.

The dispenser Envelopes 63, Fig. 1, loaded onto the carriage in position A are carried up over the idler sprockets through position B where as the envelopes continue in motion the dispenser is actuated to move into dispensing or operating position and deliver to each envelope a charge of coating ingredients. Referring now to Figures 1, 6-12, it is seen that dispenser 21 is supported on a platform 61 spaced above conveyor 20. As is apparent in Figure 6, platform 6! has an opening 68 and supports on one side of this opening a tubular column 59 on which is mounted a vertically movable slide 16. Also positioned on platform 67 and adjacent tubular column 69 is an air cylinder H which is vertically positioned and has a piston rod 12 rigidly connected to a shelf Ina integral with or connected to slide it. Also connected to the piston rod "E2 of the air cylinder and opposed thereto is a piston rod '13 of a hydraulic cylinder 14 connected to tubular column 69 at the upper ends thereof. Collar 35 is rigidly mounted on tubular column 69 adjacent the lower end of hydraulic cylinder M. Hydraulic control valves l6, l! are mounted one on each side on collar 75. Each control valve has a stem l8, 19 carrying a roll 88, 8|, respectively. Spaced from each of the rolls 80, iii is a backing 6 roll 82, 83 adjustably connected to and rotatable on collar [5. Connected to shelf 10a intermediate the piston 12 and slide 10 are two upstanding cam rods 84, 85. As is most clearly shown in Figures 6 and '7, cam rod 84 passes between valve stem roll and backing roll 82; these rolls being in rolling engagement therewith while cam rod 85 extends between roll BI and backing roll 33. The cam rods being pivotally connected to shelf 10a,

their lateral displacement is controlled by backing rolls 82, 83. Thus, it is seen that the backing rolls together with cam rods 84, 85 control the travel of valve stems 18, 19.

Air cylinder H has connected thereto adjacent each of its ends air lines 86, 81 connected to a source of air pressure and an exhaust line (not shown) through a solenoid actuated control valve V6. Hydraulic cylinder M is connected at each of its ends to a closed hydraulic fluid system which acts to control the operation of air cylinder H. The lower end of hydraulic cylinder 14 is, as is schematically shown in Figure 16, connected to tube 81 leading to control valve 76. The other side of control valve 76 has a tube 88 open to accumulator 89 and which is connected to one side of control valve 11. The other side of the control valve i1 is connected to the upper end of hydraulic cylinder (4 by a tube 96*. Since the amount of hydraulic fluid displaced from cylinder 1M varies as piston rod 13 enters and leaves the same, the accumulator is placed in the line to provide for this. The system is maintained completely full at all times by a suitable filler at 88a, Fig. 16. Also the system is maintained at some predetermined pressure to insure proper control.

The desirable pressure will depend upon the load involved and is readily ascertainable.

Rigidly connected to the slide 56 adjacent to the lower end thereof is an elevator frame 9! adapted to pass through the opening 68 in platform 61. Opposite tubular column 69 and positioned to the other side of elevator frame BI is an upstanding supporting column 92 which is also carried by platform 61. Connected to the upper and lower ends of supporting column 92 by means of collars 93, 94 are vertically positioned bar rails 95, 96. Rails 95, 96 terminate at their upper ends in collar 93 which supports an upwardly presented extension 91 on which is rotatably mounted pulley 98. A cable 99, threaded through pulley 98, is connected at one end to elevator frame 9! as indicated at H18 While its other end is connected at It! to a compensating weight Hi2 vertically slidable in the bore of supporting column 92. Positioned on a side of elevator frame 9! are two horizontal pins HM, I65 which extend into the passageway formed by bar rails 95, 96. Pins I54, me are vertically and horizontally displaced with respect to one another and carry rotatably mounted at their ends rolls I06 and I91, respectively. As is most clearly shown in Figure '7, roll ms is in engagement with bar rail 95 while roll H3! is in engagement with rail 96 thereby eliminating the possibility of lateral sway as elevator frame 9! travels up and down.

- Switches S5 and SB may be mounted adjacent to one another supported by a collar IE9 which is slida'ble on supporting column 92 and. which may be clamped thereon in any desired position. Both of these switches are maintained closed by the elevator frame 91 when it is in its starting or raised position. Switch S5 is a triple pole switch and as indicated in Figure 17 is connected on one side to the source of electrical current supply while on the other side it is connected in series with each of the switches S3 as will be more fully described below.

Three similar dispensing units I63, I99 and Hi? are disposed on elevating frame SI and carried thereby- Inasmuch as the construction and operation of each of these dispensing units are identical in every respect, I shall point out in detail the specific construction and operation of only one such dispensing unit and for the sake of clarity and brevity, I have indicated corresponding parts of each dispensing unit with identical reference characters in the drawings. Dispenser I98 includes a liquid holding tank having three walled off compartments III, H2 and H3, each being adapted to store a quantity of one of the ingredients to be discharged from the dispenser unit. As indicated, compartment MI is provided with an agitator H4 though any or all of the compartments may be equipped with agitators as desired. Each compartment has an outlet opening provided with a valve seat H5 while a valve stem H3 depends from the cover of each compartment and carries a valve H? which rests on valve seat H5 in sealing engagement therewith. At their upper ends valve stems H6 are each connected to a solenoid I18. The discharge openings from the three compartments are located adjacent to one another and each has a length of resilient tubing H9 in registration therewith and depending therefrom. Spaced intermediate the three tubes II?) and depending from elevator frame 9| is a rail I29 having three slideways I2I, I22 and I23. Each of the slideways is presented toward one of the tubes H9. As most clearly shown in Figure 10, tubes I I9 may be conveniently spaced 120 .apart with respect to the center of rail I29. Solenoid actuated and air pressure operated clamps I24, I25 and I25 are slidably mounted respectively on slideways I25, I22 and I23 and each encircles one of the tubes H9. E-ach solenoid actuated clamp may positioned in any desired location along the length of its slideway by means of a locking screw I21, and when deenergized pinch their respective resilient tubes H9 so as to collapse the walls thereof and make a liquid tight seal. To facilitate the location of each of the solenoid actuated clamps in its proper position, a graduated scale may be placed along rail I29 as indicated at I28. It should be understood that valve stems H6 as well as clamps E2 E25 and I26 are actuated by solenoids and operated by air pressure delivered from air cylinders not shown. The lower ends of tubes I I9 are open to the atmosphere and overhang a funnel I23, the construction of which will now be pointed out.

Funnel or mixer I28, Figures 8, 9 and 11 (of which there are three, one for each of the dispenser units) is substantially rectangular in cross section having a depending spout 523a. and carried by a cradle I29 to which it may be rigidly connected by means of straps I39 or the like. Cradle I29 is provided with four wheels SBI which run on the upper surfaces of two parallel tubular rails I32, the ends of which are sup-ported by elevator frame 9| and which extend in a direction parallel the upper course of conveyor 29. Cradle I29 may be provided with two auxiliary wheels I33, one to run along and engage the under surface of each of the tubular rails I32. Cradle I29 is provided with a depending skirt portion I34 which substantially encircles the lower portion of funnel I28. A pair of bushings I35 one on each side of skirt portion 534 are mounted intermediate the ends thereof and. to-

receive the pivots I36 of a U-shaped yoke I31 which (in Figure 11) extends around and below one end of funnel I23. The arms of the yoke extend somewhat beyond and above pivots I36 and have transverse bores I38 extending therethrough adjacent the ends thereof. As will be apparent, bores I38 are vertically disposed in one position of yoke I31 and tilted in another. A pair of rods I39 are slidable in bores I33 and depend from the arms of yoke l3'i. Collars I40 are adjustably connected adjacent the upper end of each of the rods I39 and abut against the upper surface of yoke I31 and thereby serve to support rods I39 in their lowermost position. A second ring-shaped collar I4I encircles each of the rods I39 intermediate its ends and may be clamped in an desired position along the length thereof. As is clearly apparent, collars I iI are positioned below yoke I3! while collars I4 9 are positioned above the same. Also encircling each of the rods I39 is a sliding bearing I52 each of which is vertically slidable along its respective rod intermediate the lower end of the rod and collar I4I. A stop nut I43 or the like is threaded on the lower end of each rod I39 and serves to retain sliding bearings I i2 when the same are in their lowermost position. An elongated platform lid is supported and connected at each of its ends by one of the sliding bearings M2 and has suitably positioned apertures through which rods I39 extend. Depending from platform I4 is a trigger bar I45 the center of which is substantially in alinement with the axis of funnel spout I28a and the axis of the neck of an advancing envelope 63. The vertical length of trigger bar I45 (Figure 9) is such that it depends sufficiently far below platform. [t4 and the lower end of funnel spout i28a as to be engaged by the neck of an advancing envelope 93 when the dispenser 2I is in its raised position or removed from operating position. Extending from the edge of platform I4 (Figure 12) which is presented toward funnel spout IZBa. is a U-shaped lip I43. The center line of lip I48 is also in registration with the axis of spout Etta and its arms are so spaced apart as to lie one on each side of and adjacent to spout An adjustable set screw I 41 is centrally mounted on yoke I37 and engages a stop I48 carried by cradle I29 so as to control the maximum rotation out of horizontal position of yoke I3'I about its pivots I 38. Thus the amplitude of the are described by rods I39, platform I44 and trigger bar M5 is a function of the distance from the end of stop screw I47 to stop I43 when yoke I3"! lies in a horizontal position.

A drip collector may be provided to catch drippings from spout I23a after it has been raised. Supported by skirt I34 of cradle I29 and extending transversely below funnel I28 (Figure 11) are a pair of rods I49, I59. Rods M9, E59 are horizontally disposed and are connected at each of their ends to skirt I34. Depending from rod I49 and pivotally connected thereto is a pair of parallel levers I5I (Figures 8, 9). A similar pair of parallel levers I52 are pivotally connected to and depend from rod I59. Levers I5I and I52 form a parallel system and are pivotally connected at their lower ends to the arms I53 of a drip pan I54. Drip pan I54 has an inclined floor which serves to direct any liquid collected by drip pan I54 toward an opening I55 formed therein and which is connected to a flexible Waste pipe I55. A motor I5! is carried by skirt I34 of cradle I29 and has a crank I58. Interconnecting crank I58 9 and one of the levers II which supports drip pan I54 is a link I 59 having a sleeve or collar I60 connected to one end thereof and which engages said lever I5I. Motor I51 may be equipped with a one-half turn clutch so that when energized crank I58 turns 180 and then stops.

A switch SI is carried by skirt I34 and is so positioned below yoke I31 as to be thrown by the yoke when th same moves from a tilted position to the horizontal position. Switch SI may also serve to bias the yoke to its tilted position or separate biasing means in the form of a coil spring or the like may be used. Switch S2 is also carried by skirt I34 and depends therefrom so as to be closed by platform I44 after it has traveled upwardly along the rods I39 and when it reaches its uppermost position.

As pointed out, funnel I28 carried by cradle I29 is free to travel on tubular rails I32. In its starting or right-hand position (Figure 9) cradle I29 is in engagement with a switch S3 which it maintains open. Switch S3 is connected to elevator frame 9i and is positioned intermediate tubular rails I32. Another'motor I6I is mounted on elevator frame 9I adjacent the starting or right-hand position of funnel I28 and drives a pulley I62 which winds a cable I53 when motor IGI is energized and which permits the cable to unwind freely when the motor is deenergized. Cable IE3 is connected to the end of cradle I29 as at I64. In the position of the various parts shown in Figure 8, rods I39 carrying collar hi0 have been displaced upwardly with respect to funnel I28. As pointed out cradle I29 carrying funnel I28 is free to travel toward the left of Figure 8 which direction coincides with the direction of travel of the line of envelopes 63 carried by conveyor 29 and over which dispenser unit I08 is disposed. Extending from the wall of elevator frame 9| toward which the cradle and funnel are free to travel as viewed in Figure 8 are two cams I65 each of which i positioned to engage th under surface of one of the collars I49; the collars being designed to slide along the upper surface of cams I65 so long as they are in contact therewith. Positioned on the same wall of elevator frame 9| and intermediate tubular rails I32 is an emergency switch S4 which is closed by the end of cradle I29 just before it reaches the end of its free travel.

Each of the funnels is provided with a pipe I66 (Figures 8, 9) having holes or outlets I6! and which extends around the funnel just inside the lip thereof. Pipe IE6 is connected to a flexible Water conduit I53 which in turn is connected to a source of water supply through a solenoid operated valve VI.

, It is to be clearly understood that each of the dispenser units I98, I99 and III] is disposed over a line of envelopes 63 which pass thereunder as they are carried along by the conveyor. As pointe'd out hereinabove, each of the dispenser units is provided with identical parts corresponding to those described in detail in connection with dispenser unit I98. Thus, each dispenserunit has,

.for example, a corresponding set of tubular rails wi e m r f l m n e t v alinement with their funnel spouts.

further downward movement.

In operation a row of three envelopes 63 slowly approaches the dispenser moving from right to left (Figure 1), each of the envelopes being in lin with one of the trigger bars I45. As shown in Figure 9, yoke I3! is in its normal position with set screw I41 up against stop I48. Elevator 9i carrying the three dispenser units I98, I99 and H9 is in its raised or starting position. In the schematic wiring diagram, Figure 17, the

various switche and relays are shown as set just 7 prior to the engagement of the trigger bars I45 by the envelopes.

It is to be understood that the relays to be referred to are of the self-latching type while the timer, which may be mounted on the dispenser as indicated in Figure 1, is of the conventional motor driven multi-contact variety.

As each of the envelopes contacts its corresponding trigger bar I 45 and continues to be carried along by the conveyor, this motion is imparted to each of the trigger bars, thereby rods I39 carried by yokes I3 swing about their pivots I36 (Figure 11). The yokes being pivoted, their right ends swing downward and throw switches SI. As is apparent in Figure 17 one pole of each of the three switches SI is connected in series between coil KI of relay BL! and the source of electrical power supply while the other poles are connected between switch'SIi and the source. When all three of the yokes have been pivoted throwing the three switches SI, coil K2 is deenergized while K! is energized unlatching relay RLI and permitting the contacts thereof to drop down. Switch S'I being maintained closed by the cam on crank I59, the circuit is now closed to each of the drip pan motors which are now energized and rotate their cranks drawing the three drip pans out from under each of the funnel spouts I28a. After the cranks have rotated 180 switch S7 is allowed to open thus stopping the motors while switch S8 is closed by the crank completing the circuit to coil K3 of relay RLZ. When coil K3 is energized relay RLZ is unlatched permitting its contacts to drop down and complete the circuit to coil KB of valve V6 which when energized connects the upper end of cylinder 'II to the source of air pressure. Elevator frame 9| then starts down under the action of air piston rod 72 and is controlled by the opposed hydraulic system through cam rod and valve TI. As the elevator frame starts down switches S5 and S6 are opened. While the elevator frame continues downward funnel spouts I 23a enter the necks of the envelopes while the rims of the envelope necks allow the trigger bars I45 to slide by until they a-but the under surfaces of lips I46 on their respective platforms I44 and stop their I Rods I39 continue downward until their collars I4! abut platform I44 which had been previously stopped by the envelopes and arrest their further downward movement as well as rods I39. As the elevator frame continues downward, rods I39 having had their downward movement thus arrested, collars I49 are raised above cams I65. Just before'elevator frame III reaches the end of its downward travel, the platforms close switches $2, the closing of any one of which starts the discharge cycle. By connecting the three switches SI in series I insure that the dispenser will not start down until all the envelopes have come into precise Thus, being assured of the alinement of the spouts and envelope necks, I connect the three switches S2 in parallel so that closing of any one of them initiates the discharge into all three envelopes'and aeeegreo 11 failure of one or even two of these switches does not interfere with the dispensing of the coating forming ingredients.

The timer is connected, as indicated in Figure 17, to the valves and pinch clamps of the dispenser units I98, I09, and N; the corresponding solenoids of the three units being actuated simultaneously. In the present instance the timer program may be as follows. Valve VI opens and closes discharging a cushion of Water into each of the envelopes, which water is only part of the total required. Then while each of the three sets of pinch clamps I24, I25 and IE6 are closed the nine solenoids II8 are actuated raising valves Ill and allowing all tubes H9 to be filled above the pinch clamps with their respective ingredients. The corresponding pinch clamps of the dispenser units are set so as to measure equal amounts of the same ingredient. Then solenoids I I 8 are deenergized, closing valves H1 and the pinch clamps I24, 125, I 26 are opened allowing the measured quantities of ingredients to flow through the funnels into the envelopes. The pinch clamps are then closed when their solenoids are deenergized and valves VI are once again opened and closed delivering the rest of the required amounts of water. This final charge of water also serves to flush the funnels as a result of the positioning of the pipes I66 around the lips of the funnels. Just before the timer resets itself for another cycle it momentarily energizes coil K4 of relay RLZ, the contacts of which are shifted to the raised position where they are latched. With the contacts of relay RLZ raised, valve V6 is shifted connecting the lower end of air cylinder II to the source of air pressure and raising the elevator frame.

During the discharge cycle envelopes 63 have been continuously moving to the left in Figure 8 and the three cradles 129 with funnels I23 therein have been moving in the same direction. Cams 1'65 are of such length that before the elevator frame starts up collars I49 on rods I39 have been carried over their respective cams and are maintained raised even though platforms I44 are no longer being supported by the rims of their respective envelopes. With the trigger bars I45 being thus maintained raised envelopes 63' which have just received a charge of coating forming ingredients are free to be carried past thereunder. As the elevator frame reaches its fully raised position switches S and S6 are closed. Since switches S3 are normally closed the circuit is now closed to each of the funnel return motors IBI which now wind their cables I63 to return each of the funnels to their starting positions. As each funnel reaches its starting position the end of its cradle opens its switch S3 thus deenergizing its motor. When all of the funnels are returned all of the switches S3 are opened. After the funnels have started to move to the right under the influence of their cables, collars I46 are carried off of their respective cams I65 and rods I39, platforms I44 and trigger bars I45 are now free to drop down into position to be acted upon by the next row of envelopes. During the raising of elevator frame 9!, trigger bars I45 were carried up out of engagement with the envelope necks thus permitting yokes I37 to pivot and throw the three switches SI back to the position indicated in Figure 17. When switch S6 was closed as the elevator frame reached its raised position the circuit to coil K2, of relay RLI was completed, energizing the same and shifting the contacts of this relay to the raised position.

12 With the contacts of relay RLI raised and since switch S8 has been closed during the discharge cycle, the circuit to the drip pan motors i? is completed and the drip pans are returned to their positions underneath spouts IZBa. On completion of the revolution of crank I58 necessary to return the drip pans, switch S8 is opened While switch S7 is closed. The dispenser is now ready to repeat the same cycle on the arrival of the next row of envelopes.

Switches S4 are provided as emergency raise switches in the event the timer should fail to .energize coil K4 of relay 'RLZ before any one of cradles I29 has reached the end of its free travel along its rails. It is apparent from Figure 17 that should anyone of the switches 54 be .closed, coil K4 is energized thus causing the raising .of the elevator frame irrespective of the setting of the timer and thus avoiding damage to the apparatus or to the envelopes. Similarly, triggers I45 and yokes I81 insure alinement of all the spouts with their envelopes before the elevator frame can start down.

After having been charged with coating forming ingredients by the dispenser, the envelopes continue to be carried along the path of the upper course of the conveyor. The length of this path is such that at the speed at which the envelopes are traveling they do not reach position C at the end of the upper course until the coating or screen forming particles have settled out of solution. As the envelopes are carried beyond position LC, they are gradually tilted to an inverted position when they arrive at D. During tilting excess liquid is poured out of the envelopes which is caught by splash guard 66 having channel 68a which leads off the waste liquid.

This pour off must be carried out very slowly, otherwise the settled screen will slip to become uneven. It must also be carried out continuously, since any hesitation in the action will cause a line on the screen where the surface of the pouring liquid hesitates.

To aid in the accomplishment of the first of these the sprockets are large enough to give the desired slow speed of pour off with the best speed of settling. In the present example this is a pitch diameter of 39 inches. The second condition is inherent in the operation of the rest of the machine, i. e., continuous motion of conveyor without harmful vibration or hesitation. In the present instance the travel of the chains and hencethe upper and lower courses of the conveyor may be set at four inches per minute.

Rinse and dry Next to be considered is the apparatus for setting the coating which may include as a preliminary step the washing and rinsing of the envelope followed by drying of the coating. Referring now to Figures 1 3, '14 and '15, it is apparent that tube envelopes {it are carried inverted through the wash and rinse position 22 as well as dry position 23. A substantially rectangular platform 2% has upstanding side walls .Zfii and end walls 263, 2914 forming a rectangular tank open at the top. As will be pointed out hereinafter platform 26%] is vertically reciprocating in operation and therefore the tank walls are of such height that they do not interfere when in their top most position with the passage of envelopes 63. Platform 2% is supported adjacent each of its corners by four identical and parallel linkages or link systems 265, 296, 201, 168 each of which comprises a long link 209 and a short link 210 one- 'or slideway 2l3.

ment with the sliding biock of linkage 208.

the other end 225 is connected to exhaust.

at which platform 203 ascends. similarly located in connection with another cam 232a carried by bar 253 and controls the rate of .20. come into registration with the longitudinal or vertical axis of the envelopes that pass in- 13 half the length of link 209. Each link 209 is pivotally connected as at 2H to platform 200 adjacent each corner thereof, while the opposite ends thereof are each pivotally connected to a slide block 2l2 free to slide horizontally in a frame The lower or left hand ends of links 2E0 looking in the direction of Figure 13 are pivotally connected to fixed blocks or lugs 2 l 4- and at their opposite ends are pivotally connected to the center of the corresponding long links 239 as indicated at 2l5. The sliding blocks 2I2 of linkages 205 and 205 are operatively interconnected by means of a rod or tie bar 2l6 while the slide blocks of linkages 201 and 208 are connected by rod or tie bar 2| 1. Tie bar 2 I 1 extends through a bore 2 I 8 in a bridge 2 I 9 connected to or integral with a yoke 220. One end of yoke 220 is in faceto-face engagement with the sliding block of linkage 207 while the other end thereof is in engage- On one side, bridge 2 I9 is connected to piston rod 22! and piston 222 which is free to reciprocate in cylinder 223. Cylinder 223 is connected at 224 and 225 by means of suitable pipes to a solenoid operated valve V2 which, in turn, is connected on one side to a source of air pressure and on the other to an exhaust pipe. As will be more fully pointed out hereinbelow, solenoid operated valve V2 is connected to a source of electrical power supply through switches SH) and Si I. For one operative position of valve V2, end 224 of cylinder 223 is connected to the source of air pressure while In the other position of valve V2, end 224 is connected to exhaust and end 225 is connected to air pressure. As is clear from Figure 14, tie bar 2 l is also connected to yoke 220 by means of bars 253 and 254. To permit fine adjustment of the rate of rise and descent of platform 200, yoke 220 is connected to piston rod 226 of piston 22! free to reciprocate in cylinder 228. As schematically indicated in Figure 14, the ends of cylinder 228 are connected through a conduit 229 having an accumulator 230 in the line. Cylinder 228, conduit 229 and accumulator 230 are filled with a suitable hydraulic fluid and the rate at which piston 22! may reciprocate is controlled by the hydraulic fluid, the passage of which, from one side of the piston to the other, is regulated by valves 231 and 232. Valves 23! and 232 are of the type which adjustably control the flow of hydraulic fluid in one direction while permitting the fluid to freely flow therethrough in the opposite direction.

Thus, the control plunger of valve 231 is conveniently placed in contact with one suitably designed cam 23 la on bar 253 and controls the rate Valve 232 is descent of platform 200.

.On platform 200 are two rows of spouts 233 x'and234. It is to be understood that there are as many spouts in each row as there are envelopes 63 in each row of envelopes across the conveyor Also, the spouts are so disposed that they .verted over :them. The spouts arepreferably mounted on flexible rubber holders 235 to relieve the strain on the neck of the envelopes 1 should one come into contact with aspout. Thus,

as indicatetkthere maybe six such spouts all of which are connected to a header 236 which, in turn, is connected to a source of washing solui? tion" by means of flexible tubing 236a through a.

14 solenoid operated valve V3 which is also actuated by the closing of switch SIB. Spouts 233 and 234 are closed at the upper ends and have downwardly directed passages formed in their walls through which liquid is directed downwardly at the necks of envelopes 63 into which the spouts have been inserted. Concentric with the spouts and adjacent the upper ends thereof are arcuate tubes 231 which have inwardly directed perforations and which are also connected to the header 233. This permits simultaneous washing of the outer surfaces of the envelope necks with the washing of the inner surfaces thereof.

Switch SIO is supported by frame 24 in such position that it is actuated by each actuator bar 65 to bring platform 200 up and carry spouts 233 up into the necks of one row of envelopes while spouts 234- are carried up in the necks of the preceding row of envelopes; thus, each row of envelopes is washed twice, once by spouts 233 and once by spouts 234. Switch SH may be mounted on frame 24 in such position that it is actuated by trip 238 connected to end wall 203 and is closed by the trip 238 as platform 200 arrives in its topmost position.

Positioned beyond wash and rinse platform 200 in the direction of travel of the lower course of conveyor 20 and to the right of platform 200 as shown in Figure 13, is an air-dry platform 239 which is supported on a system of four parallel linkages identical in all respects with those described in connection with platform 200. Furthermore, the linkages of platform 239 are actuated by compressed air and controlled by a hydraulic system also identical in every respect with that shown and described in connection with wash platform 200. Thus, platform 239 is supported by four linkages 305, 306, 301, 308; corresponding pairs of which are interconnected by tie bars 3l3 and 3. Tie bar 3|! extends through a bore 318 in bridge 3l9 of yoke 320. Yoke 320 as in the case of yoke 22B, is connected on one side to a piston rod and piston 32| and. 322 which reciprocates in air cylinder 323. On the other side, yoke 320 is connected to piston and piston rod 328, 32 0, which reciprocate in cylinder 328. Ends 324 and 325 of cylinder 323 are connected through valve V5 to a source of air pressure or an exhaust line in accordance with the setting of valve V5. The detailed construction of these various parts will be apparent from an examination of the elevating mechanism of platform 200 and is, therefore, not repeated here.

Movably mounted'on platform 239 and free to travel between the ends thereof is a dry rack 240 mounted on wheels 2M and which carries rows of air spouts 242 and 243. As in the case of spouts 233 and 234, the number of spouts in each row 242 and 243 is the same as the number of envelopes in each row across conveyor 20. Furthermore, the spouts are positioned so as to be in registration with the envelopes which successively pass over them. The air spouts may be suitably interconnected adjacent their lower ends by a system of conduits which is, in turn, connected to a source of compressed air by means of flexible tubing 244 through a valve V4. Depending from the right hand end or leading edge 240a of air rack 240 in a pin 245 which extends downwardly through an elongated longitudinal slot 243 in the floor of platform 239 As stated, air rack 240 is movable on platform 239 from left to right and back again. Positioned below platform 239 and having its center somewhatto the right of edge 240a. of the air rack when the air rack is in its extreme left hand position is a rotatably mounted sprocket 2.471. A motor and sprocket 248 is disposed below platform 2.39 and to the right .of the right hand .end thereof. Sprockets 247 and .2 58 carry .an endless chain 249 stretched between them. A plurality of spaced pins 250 are mounted on chain 249 and project horizontally therefrom. Sprockets 247 and 2.48 are so disposed with respect to slot 246 that pin 2415 extending down through slot 2:15 may be engaged by one of the pins 256 on the upper course of chain 249 when the platform is in its lowered position. Motor and sprocket 248 drive chain .259 so that its upper course travels to the left in the direction of Figure 1.3 or counterclockwise.

Valve V5 is connected to a source of electrical powersupply through switches S12, S13, S14 and S15. Switch S12 is disposed on frame 24 so .as to be closed by each moving actuator bar 55 .as it passes the same. Switch S43 which is normally closed is also supported on frame 2d and is so spaced .apart from switch S12 as to be opened by one of the actuator bars a short time interval after switch S12 has been closed. Switch S14 is mounted adjacent the left hand end of platform 239 and is maintained closed so long as air rack 2 3i! is .in its starting or left hand position. Switch S15 is mounted adjacent the other end of platform 213.9 and is closed by air rack 2418 .as the same approaches its terminal position. Switch S18 is mounted on platform 239 to the right of or beyond switch S15 and acts as an emergency switch in the event switch SR5 fails to function properly when closed by the air rack.

Flexible air tube 2'44 is connected to its source .of compressed :air through solenoid actuated valve V2 which is open when a switch S1? is closed. Switch S17 is so disposed on the supporting frame as to be closed by platform 239 when the platform reaches its raised position. Air rack 24!) has centrally positioned on its left hand end looking in the direction of Figure 13 a tongue :1 which is releasably engaged by a latch 2'52 disposed in alinement therewith on the left end of platform 239 and which serves to releasabiy retain air rack 2 10 in its starting position when it has been returned thereto by chain 249. Supported on the sides of the air rack 2 50 are two alined elongated fingers 255 which extend upwardly and are of such length as to come into engagement with the connecting rod 52 of the carriage it which is in alinement with air spouts 242. Fingers 255 are of sufiicien-t size and strength as to transmit the motion of the carriage with which they are in engagement to air rack 240.

In operation, after the envelopes have passed from -G to D around the left hand end of the conveyor and have had excess liquid removed they arrive at position E where the actuator bar of each row closes switch S10 in passing. Switch Ste is connected to the source of current on one side and on the other side to coil K? of relay RL3 through a time delay relay TD. 'Vfhen switch S19 is closed coil K! is momentarily energized to 'unlatch the relay and allow its contacts to fall and is then deenergized by the action of time delay relay With the contacts of relay R=L3 down, coil Kd of valve V2 isenergized shifting the valve so that the end 225 of cylinder 223 is connected to a source of air pressure while end 224 thereof is open to exhaust. This drives piston 2 22 to the left. Piston 222 being connected through its piston rod 221, bridge 219 and yoke 220 to both tie bars 216 and 21 1, its motion is transmitted through the four parallel linkages to platform 26*] and elevates the same. The function of time delay relay or circuit breaker TD is to insure that coil K? has been deenergized before platform 2% reaches its fully raised position. Since the envelopes continue in motion the Wash and rinse time is relatively short. Simultaneous with the shifting of valve V2 by relay RLS, coil K11 of valve V3 is energized starting the flow of wash solution through spouts 233 and 2312 which are carried up by platform 29!] into the necks of the overhanging envelopes. As platform 26f! reaches its operating or highest position it engages and closes switch S11 6 7 ergizing coil K3 of relay RL3 which raises the contacts of this relay. Coil K11 of valve V3 is .deenergized while coil K10 is energized shifting valve V2 which now connects the end 224 of cylinder 223 to air pressure while end 225 thereof is connected to exhaust. Piston 222 is now driven to the right and platform 2% is carried down to its starting position. It is to be understood that switch S 1 l] is so positioned that when it is closed by one of the actuator bars, the envelopes carried by the carriage of which said actuator bar is a part are in registration with spouts 233 while spouts 234 are in registration with the envelopes of the next preceding row.

As the envelopes continue in motion the actuator bar of their carriage next engages and closes, in passing, switch S12. Immediately after switch S12 is closed, switch S13, which is normally closed, is opened by the actuator bar of the carriage next preceding the one which closed switch S12. Thus, if air rack 241! is in its left hand or starting position and is therefore maintaining switch S14 closed, coil K12 is momentarily energized releasing the contact of relay BIA and permitting them to drop out. In this position of relay RLA, coil K14 of valve V5 is energized shifting this valve in the same manner coil K9 shifted valve V2. The elevating mechanism of platform 239 being identical to that of platform 2213, its operation will be understood from the foregoing description of the elevation of platform 2%. As platform 239 reaches its OD- erating or raised position fingers 255 carried by air rack 248 are interposed in front of connecting rod 52 of the carriage which closed switch S12, the motion of this carriage being imparted to air rack 24!! which is free to travel on platform 239 in the same direction the carriage is being carried by the conveyor. Also as platform 239 reaches its operating position it closes a switch S1! energizing the coil of valve V4 starting the flow of drying air to spouts 242, 2 13. By the raising of platform 239 into operating position spouts 242 are carried up into the row of envelopes carried by the carriage which closed switch S12 while spouts 243 are carried up into the next preceding row of envelopes carried by the carriage which opened switch S13. As air rack 240 approaches the end of its free travel its right hand end (Fig. 13) closes switch S15 energizing coil KM and raising the contacts of relay RLli. With the contacts of relay RL i raised .coil K18 of valve V5 is energized shifting the valve and reversing the elevating mechanism of the dry platform 23.9 causing the same to be low- ;ered. As platform 2.39 is lowered S1! opens deenergizing the coil of valve V4 and shutting off the flow of drying air. When platform 239 is back in its starting .or fully lowered position, pin .2215, depending through slot 246 from the end Of air rack 2.40, is engaged :by one of the Projectin 17 pins 250 on chain 249. With pin 245 thus engaged air rack 240 is carried back to its starting position where its left hand end closes switch SH and tongue 25I is engaged by clamps 252.

By arranging switches 'SIZ, SI3 and SM as described hereinabove, I avoid the possibility that the air platform will be raised except when the air rack 240 is in its starting position when switch SI2 is first closed. Thus if the air rack is not in its starting position when SIZ is closed'and fails to return before switch SIS is opened, a late return of the air rack will not close the circuit to start the dry platform up. The time interval between the closing of SI 2 and the opening of BB is such if the dry platform goes up during :that interval the air spouts will be in line with the en velopes and will enter their necks. When 5'3 has been opened the envelopes have travelled so far as to place them out of alinement with the air spouts. The required drying time is usually so long that in the present instance itis convenient to accomplish the drying of tworows of envelopes simultaneously. The drying time may be lengthened or shortened as desired by increasing the number of rows of air spouts and providing for a correspondingly longer travel for the air rack or by decreasing the same. The purpose of switch S14 is to prevent the .closing of the circuit-to valve V5 except when the air platform and the air racl: are in their starting positions.

After the coatings .or screens have been dried the envelopes continue to be carried by their carriages and holders along the path described by the lower course of conveyor 20 until they return approximately to position A. At position A the air valves of holders 58 may be manually opened and the envelopes removed from the holders.

In Figure 4, I have shown another form which the holders for the envelopes may take. lhus, instead of endless tubing 62, I may provide two fingers I12 mounted adjacent to the open end. of a holder I13. A third finger I14 is preferably mounted on the wall of holder I13 intermediate fingers I12 and has connected to it an adjusting screw I15 which is in threaded engagement with the wall of holder I13. At its outer end screw I15 carries a thumb piece I16 by means of which finger I14 may be readily adjusted. When this type of holder is used it is mounted on carriages as hereinbefore described with respect to holders 58. 'With adjusting screw I15 unscrewed or turned out somewhat, an envelope may be inserted into holder I13. Then the adjusting screw is turned in until all of the fingers I12 and I14 are snug against the side of the envelope. In view of the somewhat conic outline of such objects the base thereof is of larger diameter than the point around which the fingers are disposed and they therefore prevent the envelope from slipping out of the holders even when it is tilted or inverted. Screw I15 need only be tightened sufficiently to remove free play from the envelope with respect to the holder and should not be so tightened as to damage the object.

Instead of guide plates 40 (Figs. land 2) having guide 42 I may provide guides in the form of flexible belts or straps I10 (Figure 5') at each of the ,four corners of conveyor 20. Such guide belts I10 may be connected at their ends to a suitable bracket on the conveyor frame through sufliciently strong biasing means such as coil springs "I. When such guides are utilized, upper rails 41 are provided with areuate extensicns 41a which terminate above the lower rails ISO and spaced therefrom by a distance equivalent to the outside diameter of rolls 5 I, 52 of carria es 48. Those carriages which are passing around the ends of the conveyor jrails are maintained thereon by the action of guide belts I10 on guide rolls 51, one of which projects outwardly from each of the two trucks 5B of carriages 4B, the guide belt being positioned adjacent the rails for this purpose.

"While .I have indicated the preferred embodiments of my invention of which I am now aware and have also indicated only on specific application for which my invention .may be employed, it will be apparent that my invention is by no means limited to the exact forms illustrated or the use indicated. but that many variations may be:made in the particular structure used and the purpose for which it is employed without departing from the scope of my invention as set forth in the appended claims.

What Iclaimis:

1, In an automatic apparatus for applying coatings :to surfaces of objects, carrier means adapted to carry said objects, means for moving said carrier means in one direction along a predetermined path at a substantially constant speed, dispensing means movably disposed adjacent said path, means for intermittently moving said dispensing means down into Operating position as said objects come into registration therewith, setting means disposed adjacent said path beyond said dispensing means, said setting means including movable means, means for moving said movable means parallel to said path for a predetermined distance when said setting means is in operating position, reversible means for moving said setting means into operating position and including a valve responsive to an electrical impulse, said reversible means moving said setting means into operating position on one settin of said valve and moving said setting means back to starting position on the other setting of said Valve, and switch means connected between said valve and a source of electrical current supply and positioned to be actuated by said carrier means and said movable means.

2. In an automatic apparatus for applying coatings to surfaces of objects, carrier means adapted to .carry said objects, means for moving said carriermeans in one direction along a predetermined path at a substantially constant speed, dispensing means movably disposed above said path, setting means movably disposed below said path, said setting mean comprising at least one platform, a system of parallel linkages pivotally connected adjacent its upper ends to said platform and adapted for mOViHg the same toward said path into operating positions and away from the same, a rack movably mounted on said platform .and movable substantially parallel to said path, said rack having a spout, air pressure means connected to said system of parallel linkages adjacent the lower ends thereof for raising said platform and moving the same in said one direction, hydraulic means opposed to said air pressure means and connected thereto for lowering the platform, means connected to said rack and adapted to be engaged by one of said carrier means when said platform is in operatin position, whereby said spout is adapted to engage one of said objects, and to move said rack substantially parallel to said path when said one of said objects is so engaged, means for actuating said air pressure means to move said platform into operating position as one of said carrier 19 means passes a predetermined point along said path and to return said platform to starting position when said rack reaches a predetermined point along said platform, whereby said spout is adapted to be placed in registry with said one of said objects prior to engaging the same, and means for returning said rack to its starting position when said platform is in its starting position.

3. In an automatic apparatus for applying coatings to surfaces of objects, carrier means adapted to carry said objects, means for moving said carrier means in one direction along a predetermined path at a substantially constant speed, dispensing means movably disposed above said path, means for movin said dispensing means down into operating position when said objects pass a predetermined point along said path, setting means movably disposed below said path, said setting means comprising at least one platform movable toward said path into operating position, a rack mounted on said platform and movable relative thereto in a direction parallel to said path, said rack having at least one nozzle fixed thereto, said platform having an elongated slot formed therein, a pin depending from said rack and extending through said slot, rack return means disposed below said platform and adapted to engage said pin when said platform is in its starting position and said rack is removed from its starting position, means connected to said rack and extending upwardly therefrom adapted to be engaged by said carrier means when said platform is in operating position, whereby said nozzle is adapted to be placed in registry with and to engage one of said objects, and means for moving said platform into operating position when said carrier means pass a predetermined point along said path and for returning said platform when said rack reaches a predetermined point along said platform.

4. In an automatic apparatus for applying coatings to surfaces of objects, a conveyor having endless chains forming a horizontal upper and lower course, a plurality of carrier means pivotally connected in spaced relation to said chains and adapted to be supported by said conveyor, means for driving said chains in one direction at a substantially constant speed, each of said carrier means being adapted to releasably clamp and carry a plurality of said objects in a substantially alined row, setting means disposed below said lower course, means for intermittently moving said setting means upward into operating position and actuated as said carrier means pass predetermined points along said lower course, a vertically movable elevating frame disposed over said upper course, a plurality of dispenser units on said elevating frame one for each of said objects carried by said carrier means in a row and adapted to discharge measured doses of coating forming ingredients in liquid suspension, a plurality of horizontally movable funnels one for each of said dispenser units and supported by said elevating frame, each of said funnels having a spout depending below said elevating frame and adapted to enter one of said objects when in registration therewith, a plurality of trigger means one for each of said funnels and pivotally connected to the same, each of said trigger means extending below the spout associated therewith and adapted to be engaged and pivoted by one of said objects until said spout is in registration with said object and then to move said funnel in said direction and maintain said spout in registration with said object, a plurality of drip collecting means one suspended below each of said funnels and movable from a starting position under said spouts to a second position away from said spouts, means for moving said drip collecting means to said second position when each of said trigger means has been pivoted, means for moving said elevating frame down toward said upper course actuated by said drip collecting moving means when each of said collecting means has been moved to said second position, timer means for actuating said dispenser units to discharge said doses, and actuated when each of said spouts is in dispensing position in said objects, said elevating frame moving means being actuated by said timer means at the end of said discharge to raise said elevating frame back to its starting position, funnel return means mounted on said elevating frame and adapted to return each of said funnels to starting position, said funnel return means and said drip collecting moving means being actuated to return said funnels and said drip collecting means respectively to starting position when said elevating frame returns to its starting position.

' 5. In an automatic apparatus for applying coatings to surfaces of objects, a conveyor having endless chains forming a horizontal upper and lower course, a plurality of carrier means pivotally connected in spaced relation to said chains and adapted to be supported by said conveyor, means for driving said chains in one direction at a substantially constant speed, each of said carrier means being adapted to releasably clamp and carry a plurality of said objects in a'su bstantially alined row, setting means disposed below said lower course, means for intermittently moving said setting means upward into operating position and actuate-d as said carrier means pass predetermined points along said lower course, dispenser means vertically movably disposed up above said upper course and adapted to discharge measured doses of coating forming ingredients in liquid suspension into each of said rOWs of objects as they pass under said dispenser means, said dispenser means having a plurality of spouts one for each object in said row, said dispenser means including drip collecting means suspended below and associated with each of said spouts and movable from a starting position under said spouts to a second position away from said spouts, means for moving said drip collecting means to said second position when said objects are in registration with said spouts, means for moving said dispenser means down toward said upper course into dispensing position when said drip collecting means are in said second position and actuated by said drip collecting moving means, means for actuating said dispenser means when the same is in dispensing position to discharge said doses, said last mentioned means being adapted to actuate said dispenser moving means at the end of said discharge to return the same to starting position, and said drip collecting moving means being actuated when said dispenser means returns to starting position to return said drip collecting means to starting position.

6. In :an automatic apparatus for applying coatings to surfaces of objects, a support, a pair of coaxial drive sprockets rotatably mounted at one end of said support, a pair of coaxial idler sprockets rotatably mounted at the other end of said support each of said idler sprockets being in alinement with one of said drive sprockets, a pair of endless chains one in mesh with. each set of alined drive and idler sprockets, said chains forming an upper course and a lower course, upper rails supported by said support and extend ing parallel with and adjacent said upper course, lower rails supported by said support and extending parallel with and adjacent said lower course, each of said lower rails being disposed in alinement with and below one of said upper rails, a plurality of carriages each pivotally connected to said chains and adapted to be movably supported on said rails, each of said carriages being transversely disposed with respect to said chains and including a guide member on each end thereof and opposed one to the other, arcuate guide means extending between the corresponding ends of the alined upper and lower rails for engaging said guide members and supporting said carriages when they are in transit between said courses, means for driving said drive sprockets at a constant uniform rate, dispensing means movably mounted adjacent and above said upper course for dispensing coating forming ingredients, setting means movably mounted adjacent and below said lower course for setting the coating formed from said ingredients, means actuated when a carriage passes a predetermined point along said upper course, for successively moving said dispensing means toward and away from said upper course, and means actuated when a carriage passes a predetermined point along said lower course for successively moving said setting means 1 toward and away from said lower course.

7. In an automatic apparatus for applying a coating to an inner surface of a hollow object, a movable support for said object, a dispenser for charging the interior of said object with a suspension to form a pool thereof containing a coating material adapted to settle from said suspension when said pool is free from agitation, setting means spaced appreciably from said dispenser, and means for moving said support at a vvl substantially constant and relatively low rate of speed from said dispenser to said setting means to prevent agitation of said pool, whereby said coating material settles uniformly from said suspension on said inner surface during movement of said object.

8. In an automatic apparatus for applying a coating to a surface of an object, a movable support for said object, a dispenser having a movable feed member adapted to charge said surface with a suspension containing a coating material, means for moving said feed member toward said object in an intermittent movement for charging said object with said suspension, a trigger bar extending from said dispenser and adapted to be triggered by said object for actuating said lastnamed means, a setting means adjacent said path and spaced from said dispenser, an actuating bar extending from said support and a switch in the path of said actuating bar, said setting means including a power transfer mechanism adapted to be actuated by said switch for intermittent movement of said setting means towards said object for setting the coating applied thereto, and means for moving said object at a substantially constant speed from said dispenser to said setting means, whereby said coating material is adapted to settle from said suspension during at least a portion of the travel of said object between said dispenser and setting means.

9. In an automatic apparatus for coating a surface of an object, a movable support for said object, means for moving said support at a substantially constant speed in a predetermined path and direction, a dispenser adjacent said path and having a feeding member for charging said object with coating material, said feeding member being disposed above said support, said support being adapted to carry said object into axial registry with said feeding member, a trigger bar extending from said dispenser and spaced from the axis of said feeding member, said dispenser including mechanism adapted to be actuated by said trigger bar for lowering said feeding member toward said support, whereby said feeding member is adapted to be in axial registry with said object when said member is in lowered position for a feeding operation, and a setting means, said support extending from said dispenser to said setting means, whereby said coating is adapted to settle rom said material on said surface during travel of said support from said dispenser to the setting means.

10. In an automatic apparatus for coating a surface of an object, a movable support for said object, said support having transverse members, a dispenser disposed adjacent said path for charging said object with a coating material, a setting means spaced from said dispenser, means for moving said support at a substantially constant speed from said dispenser to said setting means, whereby said coating is adapted to settle on said surface from said coating material, said setting means being disposed below said support and including :an upwardly extending finger adapted to engage one of said transverse members, said setting means including a movable carriage havin said finger, whereby said carriage is adapted to be moved with said support during a setting operation.

11. In an automatic apparatus for applying coatings to surfaces of objects as described in claim 1, wherein said switch means includes three switches connected in series across a power supply for actuating said valve to said one setting thereof when closed, a pair of said switches being positioned to be actuated by said carrier means, one of said pair of switches being normally open, the other of said pair bein normally closed, said other of said pair being positioned beyond said one of said pair of switches for opening after the other of said pair of switches is closed, said pair of switches being simultaneously closed only while the carrier means which closed said one of said pair of switches is in registration with said movable means, the third of said switches being normally open and maintained closed by said movable means when the same is in starting position.

JAMES B. LINDSAY.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 991,433 Edison May 2, 1911 1,110,990 Provandie Sept. 15, 1914 1,266,669 Eberhardt May 21, 1918 1,787,984 Hippenmeyer Jan. 6, 1931 2,084,093 Kronquest June 15, 1937 2,281,079 Rollins Apr. 28, 1942 2,313,040 Alling et al. Mar. 9, 1943 2,316,972 Pond Apr. 20, 1943 2,322,211 Albright June 22, 1943 2,329,024 Albright Sept. 7, 1943 2,383,023 Sykes et al. Aug. 21, 1945 2,429,130 Hockman et al Oct. 14, 1947 2,539,802 Weiskopf Jan. 30, 1951 

